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<head><meta charset="utf-8"><title>Rustc compilation times · general · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/index.html">general</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html">Rustc compilation times</a></h3>

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<a name="187764889"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187764889" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187764889">(Feb 09 2020 at 16:44)</a>:</h4>
<p>Out of curiosity, how long does iterating on rustc take on your machine? I'm currently running <code>time ./x.py test src/test/ui</code> and i'm about 10 minutes in, still compiling</p>



<a name="187764911"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187764911" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187764911">(Feb 09 2020 at 16:45)</a>:</h4>
<p>I'm on a laptop though, so i'm not expecting anything exceptional</p>



<a name="187765354"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187765354" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187765354">(Feb 09 2020 at 17:00)</a>:</h4>
<p>15-20 minutes on a ryzen 1800x (8 core/16 thread) for a build to stage 1 std</p>



<a name="187765361"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187765361" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187765361">(Feb 09 2020 at 17:01)</a>:</h4>
<p>and that's with cached llvm</p>



<a name="187768426"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187768426" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187768426">(Feb 09 2020 at 18:43)</a>:</h4>
<p>That's rough, on a desktop with a pretty powerful cpu... what do you do in the meantime? Context switch to another copy of rustc?</p>



<a name="187768682"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187768682" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187768682">(Feb 09 2020 at 18:51)</a>:</h4>
<p>@<strong>Matthias Prechtl</strong> Make sure you pass <code>-i</code> for incremental and <code>--stage 1</code> to only build the compiler once (one or both of these might be the default for <code>x.py test</code> nowadays). Also, I often don't run the entire test suite locally, just certain directories. I usually rely on CI to run the full suite when I feel my changes are probably correct.</p>



<a name="187768869"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187768869" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187768869">(Feb 09 2020 at 18:57)</a>:</h4>
<p>Since I work mostly in <code>rustc_mir</code>, which is pretty late in the compilation pipeline, it only takes a few minutes for a build/test cycle.</p>



<a name="187768912"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187768912" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187768912">(Feb 09 2020 at 18:58)</a>:</h4>
<p>If you are working on the AST, things will be slower.</p>



<a name="187768979"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187768979" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187768979">(Feb 09 2020 at 19:00)</a>:</h4>
<p><span class="user-mention" data-user-id="118594">@ecstatic-morse</span> thanks for the pointer, i'll try that one :) Curious why that's not the default?</p>



<a name="187769049"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769049" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769049">(Feb 09 2020 at 19:02)</a>:</h4>
<p>Not sure, maybe just intertia. You modify <code>config.toml</code> to ensure incremental is on by default (like I said, that may already be the case).</p>



<a name="187769052"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769052" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769052">(Feb 09 2020 at 19:02)</a>:</h4>
<div class="codehilite"><pre><span></span>./x.py clean --llvm-skip-rebuild TRUE
time ./x.py build
</pre></div>


<p>Takes 26min 24s</p>



<a name="187769069"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769069" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769069">(Feb 09 2020 at 19:03)</a>:</h4>
<p>On an i7-8550U</p>



<a name="187769118"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769118" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769118">(Feb 09 2020 at 19:04)</a>:</h4>
<p>I'm actually kind of impressed, given that the r7 1800X from <span class="user-mention" data-user-id="116122">@simulacrum</span> takes 15-20mins</p>



<a name="187769130"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769130" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769130">(Feb 09 2020 at 19:05)</a>:</h4>
<p>I'll try the incremental version and post an update :)</p>



<a name="187769145"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769145" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769145">(Feb 09 2020 at 19:05)</a>:</h4>
<p><span class="user-mention" data-user-id="202314">@matprec</span> incremental will only be faster when you're making changes. The initial build will be slower</p>



<a name="187769152"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769152" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769152">(Feb 09 2020 at 19:06)</a>:</h4>
<p>Do make sure you're always using stage 1 though.</p>



<a name="187769194"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769194" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769194">(Feb 09 2020 at 19:06)</a>:</h4>
<p>For almost all changes you don't need a stage 2 build</p>



<a name="187769199"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769199" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769199">(Feb 09 2020 at 19:07)</a>:</h4>
<p>Yeah that's expected :) is a newline change enough to make the incremental checker think it needs to rebuild?</p>



<a name="187769204"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769204" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769204">(Feb 09 2020 at 19:07)</a>:</h4>
<p>Because then i'll likely try a "worst case" incremental build with a change in the parser</p>



<a name="187769264"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769264" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769264">(Feb 09 2020 at 19:09)</a>:</h4>
<p>Not sure <span aria-label="slight smile" class="emoji emoji-1f642" role="img" title="slight smile">:slight_smile:</span> Feel free to try</p>



<a name="187769320"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769320" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769320">(Feb 09 2020 at 19:11)</a>:</h4>
<p>(I don't work on incremental, and <code>x.py</code> is a bit different than <code>cargo</code> so it might be relying on file timestamps)</p>



<a name="187769378"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769378" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769378">(Feb 09 2020 at 19:13)</a>:</h4>
<p>Oh, one more thing. Use <code>x.py check</code>, not <code>x.py build</code> when you're still actively developing something. It will return results much faster if there's an error in your code.</p>



<a name="187769432"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769432" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769432">(Feb 09 2020 at 19:15)</a>:</h4>
<p>10min sometimes. Maybe I'm remembering wrong too :)</p>



<a name="187769507"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769507" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769507">(Feb 09 2020 at 19:17)</a>:</h4>
<p><span class="user-mention" data-user-id="202314">@matprec</span> One more one more thing. To build just the stage1 compiler with just  the stage1 standard library artifacts, it's <code>./x.py build --stage 1 src/libstd</code></p>



<a name="187769642"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769642" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769642">(Feb 09 2020 at 19:21)</a>:</h4>
<p>If you add a <a href="https://github.com/rust-lang/rustup#working-with-custom-toolchains-and-local-builds" target="_blank" title="https://github.com/rust-lang/rustup#working-with-custom-toolchains-and-local-builds">custom toolchain to <code>rustup</code></a> (I call mine <code>stage1</code>), which points to the build directory containing the stage 1 compiler, you can run <code>rustc +stage1 file.rs</code> to test your compiler without worrying about <code>x.py</code></p>



<a name="187769688"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769688" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dylan MacKenzie (ecstatic-morse) <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769688">(Feb 09 2020 at 19:22)</a>:</h4>
<p>This means I can alternate between editing files and running individual tests without having to rebuild every time.</p>



<a name="187769976"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769976" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769976">(Feb 09 2020 at 19:33)</a>:</h4>
<ol>
<li>Build incremental rustc</li>
<li>Touch <code>src/librustc_lexer/src/cursor.rs</code></li>
<li><code>time ./x.py build -i --stage 1</code></li>
</ol>
<p>Results in</p>
<div class="codehilite"><pre><span></span>real    3m15,065s
user    13m27,142s
sys     0m42,841s
</pre></div>


<p><span aria-label="tada" class="emoji emoji-1f389" role="img" title="tada">:tada:</span></p>



<a name="187769982"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187769982" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187769982">(Feb 09 2020 at 19:33)</a>:</h4>
<p>Thanks so much, your input has been extremely valuable <span class="user-mention" data-user-id="118594">@ecstatic-morse</span> !</p>



<a name="187770085"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187770085" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187770085">(Feb 09 2020 at 19:36)</a>:</h4>
<p>I just found <a href="https://rust-lang.github.io/rustc-guide/building/suggested.html" target="_blank" title="https://rust-lang.github.io/rustc-guide/building/suggested.html">https://rust-lang.github.io/rustc-guide/building/suggested.html</a> :) Still crawling through the docs, there's just so much to absorb :D</p>



<a name="187770090"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187770090" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187770090">(Feb 09 2020 at 19:37)</a>:</h4>
<p>Yeah that guide is really helpful</p>



<a name="187845301"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187845301" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Chris Simpkins <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187845301">(Feb 10 2020 at 18:46)</a>:</h4>
<p>Is it acceptable to run tests with the <code>-i</code> flag?  For instance, <code>./x.py test -i --stage 1 [path to test module]</code>.  I am 10 mins into the compile to run one test without <code>-i</code> after an initial build... :)</p>



<a name="187846439"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187846439" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Chris Simpkins <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187846439">(Feb 10 2020 at 18:56)</a>:</h4>
<p>Significantly faster to run tests with <code>-i</code>.  Cut my time down to ~1/3 of that without it</p>



<a name="187850879"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187850879" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187850879">(Feb 10 2020 at 19:41)</a>:</h4>
<p>I'd say go for it, afaik incremental shouldn't affect the behaviour of the compiled rustc</p>



<a name="187850953"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187850953" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matprec <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187850953">(Feb 10 2020 at 19:42)</a>:</h4>
<p><span class="user-mention" data-user-id="262810">@Chris Simpkins</span> ^</p>



<a name="187851307"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/187851307" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Chris Simpkins <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#187851307">(Feb 10 2020 at 19:47)</a>:</h4>
<p>ty!</p>



<a name="188088175"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/188088175" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> RalfJ <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#188088175">(Feb 13 2020 at 08:55)</a>:</h4>
<p>I have set <code>incremental=true</code> in my <code>config.toml</code> so I don't need to pass that flag manually all the time any more ;)</p>



<a name="188088181"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/188088181" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> RalfJ <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#188088181">(Feb 13 2020 at 08:55)</a>:</h4>
<p>so, yes, definitely acceptable to set that flag for local testing</p>



<a name="188102822"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/122651-general/topic/Rustc%20compilation%20times/near/188102822" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Chris Simpkins <a href="https://rust-lang.github.io/zulip_archive/stream/122651-general/topic/Rustc.20compilation.20times.html#188102822">(Feb 13 2020 at 12:50)</a>:</h4>
<p>Ah very nice! Thank you!</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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